SAN ANTONIO - The big sky, wild lightning and barren terrain of West Texas fascinated young artist Georgia O'Keeffe when she lived in the state early this century.

Though she went on to achieve fame in New York and is forever linked to her beloved New Mexico, O'Keeffe spoke fondly of Texas and even called the state "my spiritual home."

Her attraction to the canyons and plains of the Panhandle and how the light and landscape of Texas helped shape her career are examined in "O'Keeffe and Texas," an exhibition opening Tuesday at the McNay Art Museum in San Antonio.

"Everybody always thinks of O'Keeffe in New Mexico," said Bill Chiego, director of the McNay and organizing curator of the show. "The early Texas years were . . . not forgotten completely, but not given much attention."

The McNay exhibition aims to change that.

Featuring 50 of O'Keeffe's works, the show explores pieces she did while teaching art in 1912-18 in Amarillo and Canyon. And it looks at how her later art was influenced by what she saw and the artistic styles she adopted in Texas as a woman in her 20s.

"She became fascinated by just the vastness of the space out here, and it seemed to trigger inspiration for her," Chiego said. "The ideas that she developed here she kept using, you might say, and they became sort of building blocks for lots of compositions."

Those concepts emerged in O'Keeffe's well-known paintings of flowers, clouds, animal bones and other aspects of nature, Chiego said.

"O'Keeffe and Texas" highlights five compositional ideas in her work: light, line, landforms, geometric patterns, and solids and voids.

O'Keeffe's time in Texas marked a turning point in her career, said Sharyn Udall, who teaches art history at the University of New Mexico at Santa Fe and is guest curator for "O'Keeffe and Texas."

"In Texas, she grasped the notion for the first time that she might be able to paint full time," said Udall, who has extensively studied letters O'Keeffe wrote to friends during her time in Texas.

O'Keeffe, who died at age 98 in 1986 in Santa Fe, supervised art in the public schools in Amarillo in 1912-14 and taught art at West Texas State Normal College in Canyon in 1916-18. During those teaching stints, O'Keeffe had her first exhibition at the influential Alfred Stieglitz gallery "291" in New York. She later moved to New York and married Stieglitz.

In her free time in Texas, O'Keeffe loved to walk for miles at Palo Duro Canyon. She enjoyed the plains. She marveled at the stars and moon, at thunderstorms and even at the sights and sounds of trains and cattle.

"Being in Texas exposed her to a whole range of new visual experiences," Udall said. "She had never been anywhere where space seemed absolutely unlimited."

Years later, in an interview with Katharine Kuh for the book "The Artist's Voice: Talks with Seventeen Artists," O'Keeffe spoke of her love of West Texas.

"I couldn't believe Texas was real," O'Keeffe said in 1960. "When I arrived out there, there wasn't a blade of green grass or a leaf to be seen, but I was absolutely crazy about it."

The McNay Art Museum has five O'Keeffe works in its permanent collection, including "Evening Star No. V," a watercolor done in 1917 while she was in Texas, and "From the Plains I," a 1953 oil painting described as her remembrance of the sound of cattle outside Amarillo.

"That sort of fascinated us, because we thought, `Well, why was she still painting Texas 40 some-odd years later? What kept this alive in her memory?"' Chiego said.

With those five works and two owned by McNay chairman Robert Tobin as their starting point, Chiego and his staff set out to persuade other museums and individuals to loan O'Keeffe pieces for the exhibition.

"We had a lot of convincing to do for the show because the title confused people. They didn't know about her Texas years that much," Chiego said. It took more than two years to put the exhibit together.

Among the institutions loaning art for "O'Keeffe and Texas" are the Amon Carter Museum in Fort Worth; the Georgia O'Keeffe Museum and Gerald Peters Gallery in Santa Fe; the National Gallery of Art in Washington; and the Metropolitan Museum of Art and the Museum of Modern Art, both in New York.

Among the more notable pieces in the show are "Dark Iris No. 1," from 1927; "Red Hills Lake George," 1927; "Lake George Window," 1929; and "Sky Above Clouds III," 1963.

Her works done in Texas include the 1917 watercolor "Roof with Snow" and its accompanying studies; "Train Coming In - Canyon, Texas," a 1918 watercolor; "Special No. 21 (Palo Duro Canyon)," a bold 1916 oil painting; and "Window - Red and Blue Sill," a 1918 watercolor done when she was recuperating from influenza in the San Antonio area.

"Orange and Red Streak," a 1919 oil painting, was completed a year after she left Texas and is her recollection of lightning on the prairie.

Finding the pieces wasn't easy. Some had changed hands several times among private collectors. "Any show like this is a lot of detective work," Chiego said.

Along with "O'Keeffe and Texas," which runs until April 5, the McNay is exhibiting "Georgia O'Keeffe: Canyon Suite" through March 22. The group of watercolors, painted during her time in Canyon, is on loan from the Kemper Museum of Contemporary Art and Design in Kansas City.

The McNay is bracing for a big crowd - perhaps as many as 100,000 during the main show's 10-week run - because of the immense popularity of O'Keeffe's work and because "O'Keeffe and Texas" will not travel to other museums.

Interest in O'Keeffe has intensified recently with the opening last year of the Georgia O'Keeffe Museum in Santa Fe.

Already, 12,000 students have reservations. A 20-minute videotape has been prepared for teachers bringing their pupils to the show.

In addition to discovering the Texas' influence on O'Keeffe, Chiego hopes the public learns from the exhibition about the "wonderful tension" between description and abstraction.

"A lot of the public is afraid of abstraction, but if they look at this show carefully they'll see how she saw abstraction everywhere in nature," Chiego said.

"She loved the landscape," he said. "Wherever she lived, she saw the world in a very powerful way, a rich way."

"O'Keeffe and Texas" is on view through April 5 at the McNay Art Museum, 6000 N. New Braunfels Ave., San Antonio. All tickets are timed and dated. For more information call (210) 930-4419.